From e42df8231c2815ff91a66863ae27c330153ef960 Mon Sep 17 00:00:00 2001
From: Roman Makarov <deepspiral@yandex.ru>
Date: Fri, 22 Mar 2024 17:33:17 +0300
Subject: [PATCH] fix(classname): fix zero mod value bug

---
 packages/classname/classname.ts           | 6 +++++-
 packages/classname/test/classname.test.ts | 6 +++---
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/packages/classname/classname.ts b/packages/classname/classname.ts
index 7c460b03..e30cd93d 100644
--- a/packages/classname/classname.ts
+++ b/packages/classname/classname.ts
@@ -49,6 +49,10 @@ export type Preset = {
   v?: string
 }
 
+function isEmpty(val: string | boolean | number | undefined) {
+  return !val && val !== 0
+}
+
 /**
  * BEM className configure function.
  *
@@ -81,7 +85,7 @@ export function withNaming(preset: Preset): ClassNameInitilizer {
 
           if (modVal === true) {
             className += modPrefix + k
-          } else if (modVal) {
+          } else if (!isEmpty(modVal)) {
             className += modPrefix + k + modValueDelimiter + modVal
           }
         }
diff --git a/packages/classname/test/classname.test.ts b/packages/classname/test/classname.test.ts
index 9c996cc9..ba236804 100644
--- a/packages/classname/test/classname.test.ts
+++ b/packages/classname/test/classname.test.ts
@@ -47,9 +47,9 @@ describe('@bem-react/classname', () => {
         expect(b({ modName: false, mod: 'val' })).toEqual('Block-Elem Block-Elem_mod_val')
       })
 
-      test('zero', () => {
+      test('zero string', () => {
         const b = cn('Block')
-        expect(b({ modName: '0' })).toEqual('Block Block_modName_0')
+        expect(b({ modName: '0', mod: 0 })).toEqual('Block Block_modName_0 Block_mod_0')
       })
 
       test('undefined', () => {
@@ -211,7 +211,7 @@ describe('@bem-react/classname', () => {
 
       test('zero', () => {
         const b = cCn('block')
-        expect(b({ modName: '0' })).toEqual('block block_modName_0')
+        expect(b({ modName: '0', mod: 0 })).toEqual('block block_modName_0 block_mod_0')
       })
     })
   })